INVESTIGATION OF ADSORPTION, DILATOMETRY AND STRENGTH OF LOW RANK COAL. III. INVESTIGATIONS OF SIMULTANEOUS SORPTION TOGETHER WITH EXPANSION AND DESORPTION TOGETHER WITH CONTRACTION KINETICS OF COAL UNDER THE INFLUENCE OF CARBON DIOXIDE.

The investigations of simultaneous adsorption with expansion and contraction with desorption of CO//2 on the low rank coal (80. 88 per cent of C in organic matter) have been carried out. The sorption and expansion measurements were performed at 0. 38; 0. 78; 1. 18; 1. 96; 2. 96 MPa pressures. The desorption and contraction of coal after reducing the pressure from its previous adsorption value to 0. 1 MPa were also measured. The parallelism of sorptive and dilatometric phenomena was proved. The short review of up to now concepts on dilatometric changes of coals during sorption was presented. The high rate of sorption and expansion in the first stage of the process proves the adsorption while the following slow and uniform expansion suggests the occurrence of the absorption phenomenon.